Automated test equipment or ATE, often plays a critical role in the manufacture of semiconductor devices. The equipment provides semiconductor manufacturers with the ability to functionally test each device at the wafer and packaged-device levels. ATE often includes electronic circuit boards, often called channel cards, with multichip modules or MCMs that provide the electronic circuitry for test channels. The test channels apply signals to and capture signals from one or more devices-under-test or DUTs.
The MCMs have densely packed circuitry that generates significant amounts of head. Conventionally, liquid-cooled cold plates having formed surfaces configured to match the surface topology of each board were adequate. With the tendency to pack more channel circuits into smaller chips on the boards, however, heat dissipation associated with the chips may overwhelm the cooling capacity for conventional cold plates. Moreover, cold plates tend to be heavy, comprising metal containers mounted to the surface of each board.
One possible alternative to the use of cold plates for cooling MCMs is to employ immersion cooling techniques. Coolant may be flowed through the MCM, over the chips and/or heat sink to cool the device.
While immersion cooling techniques can provide more efficient cooling, high performance modern electronic chips in the MCMs, especially those used in automated test equipment, are sometimes sensitive to temperature level and fluctuation. The coolant flowing across the chips changes temperature as it flows and may not flow uniformly, so can sometimes cool unevenly. To improve performance of these chips, a stable temperature level is desired across all the chips in an MCM. Thus, what is needed is an MCM that is capable of providing more stable and uniform cooling of the chips in the MCM.